NOTES - PLEASE READ 03:36 - This looks like a transfomer winding with a centre tap, however I checked the resistance of the winding at one point (not in the video). It turns out that resistance across the whole winding is about 20 ohms and the resistance from the 'tap' to one end is 2 ohms. At first I wondered if it was faulty, then I figured it is a tapped primary but the tap point is not in the centre of the winding. This acts as an auto-transformer (like a normal step down transformer but with no mains isolation) so that the tap winding would have 10% of the voltage across it (based on the ratio 20 ohms to 2 ohms). With a 240V AC mains supply the tap voltage would be 24V AC and this is what I think it is doing - either acting as a low voltage supply to part of the circuit or the 24V is being monitored by the microcontroller to calculate the output (240V) voltage 46:43 - This requires a little more explanation. Basically an OP-AMP, or Operation Amplifier can be considered to be an amplifier with infinite gain. This means that even the smallest difference in voltage between the + and - inputs causes the output voltage to swing between 0V and the Power Supply Voltage (in our case 12V) Used like this the op-amp acts like a switch. If we put a reference voltage on one of the inputs it acts like a voltage comparator. However we can also set the gain of an op-amp using two resistors - one feedback resistor between the output and one of the inputs, and another resistor on the same or other input. The ratio between the two resistances sets the amplifier gain. When I spotted the feedback resistor I realised the op-amp in our circuit is being used to amplify the small voltage across the current sense resistor so that the microcontroller can measure it. I will cover 'ALL YOU NEED TO KNOW ABOUT OP-AMPS TO FIX STUFF in a future video.
@03:36 If the UPS is a line-interactive one it may use the autotransformer to reduce o increase the ac output if the input is too high or low respectively.
Hi, At switch on May be it also test to see if the battery needs to be charged. I just joined your discord as Super-Grand-Ad.- Brill Video Chase to a duff battery.
The only answer I have is there is not another channel on TH-cam like yours. I was glued to my tv following along with theory. It was very enjoyable watching you go through the steps in a logical manor despite the outcome. Love your channel
The UPS's I work with on my job do this very thing - IF you install them and turn them on before you put the internal battery in, it will give an alarm and not start up. You have to turn it off, install the battery, then plug it in and turn it on. I don't understand all the internal workings of it, but even the older (15 year old UPS's) are like that. However, once you know that sequence, you tend to not make that mistake again. The UPS's I'm working with are 2kVA to 10kVA with internal and external battery packs. But from your video, even the single battery UPS's do this. I really enjoyed watching this because I have a lot of items with no schematics. I have several "doh!" moments as a result. Thanks for your channel. Really enjoying watching all your videos, and am learning a lot in the process.
Not sure but thought the original goal was to see if the board could be used/altered to become an inverter for a solar application. It seems we proved the UPS works, but did we lose track of the original goal? Love the vids! Happy when the bell goes off saying another one has been posted.
Your videos seem to be a bit long at first, but considering your knowledge and the way you explain things, these are excellent tutorial videos, i have learnt many things from your videos, and i thank you for that sir
I’m glad to see someone else have a moment like this. Now I know it’s not just me. I can’t tell you how many times I’ve spent hours chasing a theory only to find a simple solution.
Oh for sure it definitely isn't just you. I like to publish videos like this one just to show what it really is like even if you have a lot of experience. Best thing is you only get caught out once (usually) by each new situation, and learn something at the same time. I certainly did with this one
Hi Rich, Good video. The open loop gain of an OP-Amp is extremely high and we don't know if there is any loop gain control. So you can't really measure the difference on the inputs accurately enough to know if one input is greater than the other as it could be lower than the meters resolution can possibly read. If you know how the gain is set then it could be worth trying to measure the difference. Remember there are multiple ways to use OP-Amps, some examples, Inverting Amps, Non-Inverting Amps, Buffers and Voltage Followers. You would need to reverse engineer the Op-Amp circuit to see how it is being implemented to really know whats happening there. I have also been caught out trying to use a bench power supply with a UPS to find out it does not always work. I think you will find that during the power up cycle it tests the installed battery to see it it charges, takes a load and if the AC is applied. It seems they are not very efficient either. The output voltage of those Gel Cells is around 11 - 13v but the charging voltage is quoted around the 14V mark. Your last solution is definitely the way to go when testing these units. 9 out of ten times, when these units are discarded its because of faulty batteries, and the replacement batteries are almost as costly as the UPS, so they get dumped. Its quite easy to modify a UPS to use a car battery as long as you put the battery into a battery box that is in a well ventilated area. Remember car batteries contain Acid and give off hydrogen gas when charging.
I suspect that the difference between a battery and a bench PSU is that you can have current going both ways, charge and discharge, with a battery but not with a bench PSU. My guess is that the microcontroller looks to see if there's battery voltage and then switches to charging, where it monitors the charge current going to the battery. Because you were using a bench PSU, the microcontroller wouldn't see the charge current, or at least an incorrect charge current and shuts down thinking that it's connected to a faulty battery.
UPSes are non supposed to run on battery for long time so could the heatsink not be sized enough? I suggest at least to drill holes and maybe add a slow fan.
Yes that may be a good idea.. A fan and/or larger heatsink would be easy to add, especially with the internal battery removed. I need to fit some terminal posts to the enclosure anyway (to connect the battery once it is reassembled) so I'll take your advice and do that. Thanks.
I think the reason why it didn't work was, as a battery goes flat the internal resistance goes up and I think the circuitry is measuring the resistance of the battery and shuts the inverter down due to a lack of current flow. I'm still learning so it's a calculated guess.
My understanding of a battery's internal resistance is that it affects the current drawn out of the battery and the current limited into the battery. You may measure 12 volts on the battery with no load, but applying a load, you will see the voltage drop drastically. I use the "BLUE box" capacitor checker for testing the ESR on car batteries and 3V coin batteries. A TH-cam video showed it was save to use the Blue Box on battries.
I agree. But I was using my bench PSU which could deliver up to 5A and if you notice when I try to start the inverter it only draws a small amount - less than 100mA then switches off. I also tried a whole load of different voltage settings from 12V - 14.6V and it still would not start
@@LearnElectronicsRepair I’m curious if you would be able to measure the ESR of your bench power supply to see what that reading would be and maybe it would be a clue?
When you switch on ups it needs high current momentary and pure D.C. You can put large capacitor at O/P of the bench power supply, it may solve your problem.
Hi Richard. The comments from Ser Olmy and Sham Vibhute on this thread may explain what you saw. The internal resistance of a lead-acid battery would be a few milliohms, which means that its voltage will not drop even briefly. But the bench power supply perhaps doesn't have a huge internal energy store, and may rely more on internal feedback action to regulate any voltage dips under load. So if there is a sudden high current draw when the inverter starts up, the voltage of the bench supply may drop for a few milliseconds before it recovers. Something in the UPS inverter may be seeing that dip and not liking it. Did you check whether or not the 'current sense' input pin to the MOSFET controller chip stays below 1 volt when the lead acid battery is used? Maybe it's possible to see any voltage dip by looking at the bench supply with a scope set to AC coupled, and compare the depth of dip when using the lead acid battery to when using the bench supply. The idea from Ser and Sham of putting big capacitor across the DC supply could be the answer. Or perhaps find how the voltage is sensed on the control PCB, and somehow modify the dip sensor to slow it down and so fool the circuit into staying on. But then perhaps the solar cell that your friend wants to use actually have quite a low resistance so may be more like the lead-acid battery and it may just work, who knows?.
I think putting a big capacitor across the PSU output is a very good suggestion. Actually the owner brought me a second UPS to fix/modify so let's try that out soon. The 'current sense' pin on the PWM controller I think is a red herring. I didn't completely reverse engineer the UPS but I think is it pretty certain it is not being used to sense current, but is being used as an EN signal from the micro-controller to the inverter PWM
Do you have a linear or switching bench power supply? I think it does a quick power test on the battery to see if it can deliver enough power to be stable. But it does this so quickly that your bench power supply meters don't pick it up. If you had a linear power supply you would be able to hear the relays click a switching power supply doesn't do that. It is just a guess it might also do this by reading the resistance of the battery like other people commented.
Actually I have one of each - the one I was using is SMPS but I also have a linear one. The guy who owns this one brought me another UPS to repair/modify so I am going to play around with that one too. I could try my linear PSU or put a large electrolytic across the PSU output as some here have suggested.
Heya, I have a MPP Solar HV 4850 hybrid inverter. have bean wondering how that would work now I have seen a simpler virsion of what I have ( much more comment's inside, of cores I opened it and uploaded it to my youtube channel) but now I have a more clear picture of the working inside lol it thanks.
very interesting video, it was interesting to learn about current sensing and voltage sensing to enable the PWM chip. Don't worry about chasing the red herring, I think it's part of been an electronics engineer 🙂 if you're looking for content to create how about operational amplifiers as they are very common component.
Richard, are you sure this device is not designed to run with 24V batteries? I know some UPS run 2x 12v in series. Also, what is the ripple like on your bench PS?
Hi! In a previous job I had about 30 of that exactly UPS. They are crap, do no use them, I had to change many batteries every 2 years, maybe floating mode is inexistent?. Gooooood video by the way!
Every 14 days, my UPS will run a self-test. This turns on the inverter and measures what current it can draw and presumably indicate when the battery has reached the end-of-life. I assume it does a similar test when switched on. That is quite a reasonable assumption. I found out this by googling since this alarm is not documented in the manual. My battery expired and I came up with the brilliant idea of using my used car battery instead of buying a new one. However the UPS did not see the expected voltage drop and would turn on the alarm. The only way to reset the alarm is to disconnect the battery and mains, press the power on switch for a bit and then reconnect the battery and mains in that order before powering on again. Every 14-days there is this hassle and I did not like rebooting my desktop PC so I had another brilliant idea to cut the wire to the alarm/buzzer. Peace at last until one day it died completely during a lightning storm. I felt the side of the car battery and it was unexpectedly warm. I dared not use it again and purchased a new unit. Can a UPS invert indefinitely if a large enough battery bank is connected? I think maybe not. The only reason I buy such a UPS is to act as a lightning arrestor/surge suppresor. Why not just buy a surge suppressor? That is becasue each surge zaps the suppressor and eventually it does not help at all AND you don't know when that life is reached and you run out of protection. It is cheaper to sacrifice a UPS. I hope this helps explain why substituting a power supply instead of a battery is foolishness. Sorry, I did not learn anything from this video. You make too many assumptions.
I think those 8pin UC chips are emf sensitive dealing with them via low quality probes or tweezers would lead to a disaster! I have blown one chip and some mosfets during inspection.
If it senses the internal battery resistance why it needs to do it , as in safety issiues or complaint issiues when the thing underdelivers the rated output ?
@@LearnElectronicsRepair in the end of the video you mentioned that it works normally with a battery as in it might check for the internal resistance before enabling the output . And when you only used bench power supply with given volatege it refused to normally operare. I am a bit rusty on battery resistances alhough I am aware even AA batteries have it. Question is why would manufacturer design the conditions logic to work that way, if it is a cruical factor to be operated from a battery source and not otherwise.
Possibly - but seeing as the power supply was the only thing powering the circuit I can't work out how it knows the internal resistance of it's own power supply
@@LearnElectronicsRepair I had a similar issue trying to run a 24V UPS from a bench power supply. Turned out the short current spike caused by the UPS running an inverter self-test at power up was enough to trigger the current limiter of my 5A supply, which in turn triggered some battery sensing circuitry in the UPS. In my case, a 10,000µF (or it might have been 15,000µF, I'm not quite sure) capacitor in parallel with the bench power supply was enough to deal with the current spike.
I'm curious... Been workn on a project for over a year!... Can anyone find detailed wiring schmatics/pinouts for the two boards on this controller?... I can pay you in Ramen-Noodles... Jungheinrich Steuerung MP 1510 C/6 Mat Nr 50313640 Interface 50053044
@@LearnElectronicsRepair It's a battery "MANAGEMENT" system.... Probably through an algorithm of sorts embedded within one of those chips... is there not an eprom on that board?
@@TH-camSupportServices Agreed - though there was no dedicated battery management chip. There is no discrete eprom but I am sure the micro controller contains firmware. While I agree with what everyone says about somehow detecting the battery resistance (I suggested so much in the video that is why I decided to try a good battery) I can't figure out why it would not work on my bench PSU - it only draws a small amount of power
@@LearnElectronicsRepair Found the boards..I'll look at them in the light tomorrow... If I find anything similar, ..maybe I'll just mail the parts to play with em....
@@LearnElectronicsRepair no sir I'm not well in English........ As you say explinarion Deeply it feels like learners some confusion..... So I request you teach slowly for learners.... Tq
5amp warning will go off if you have less than 17amps ish the invert low power warning will not power on and beep at you. The opto coupler switch on the high current side because the current is too high to use any relay. The best way to test this is with a fully charged battery or car battery. Worked with inverters for 10 years. Also you will never use this circuit with solar without some serious thinking and or bastardisation.
The guy who runs his house completely off solar actually uses his panels to charge an array of 12V batteries. I would expect this UPS would work as an inverter from the batteries but take on board what has been suggested by others here about fitting a larger heat sink / fan. As there is a lot of space where the original battery went that should not be a problem. Other that that what other problems would you anticipate?
@@LearnElectronicsRepair Yep thanks for the reply just thing this ups is inverter is light duty and only designed to run for short periods. So yes it could be done but it's no man enough for long duty or heavy loads.
Trying 2 sign in;... create an account with Discord;... which turned out 2 B RUBBISH... Gave an email clicked all the DAM Right Images... Got a verification email Then it asked 4 a Phone number;... which sent me a code... It then asked me to sign in;... which request me to go through all the above again Then I received an email saying ACCOUNT Blocked as it has detected a BOT... So STUFF Discord...
The link works for me - I just tried it. Give it another go Learn Electronics Repair is now on Discord! Come and join the fun and let's fix stuff together, it's free and a nice place to be. discord.gg/vam6YC8vwU
@@LearnElectronicsRepair ... This time it said Log Out at the bottom... But nothing seemed to work... Log out;... then Logged back in... Then it said Account Disabled...
Discord as also sent me a email stating... ... Hello, Discord is focused on maintaining a safe and secure environment for our community. We've found your account to be in violation of our Terms of Service or Community Guidelines. As a result, we've disabled your account for the following reason: Discord has disabled your account for spam and/or platform abuse. Our anti-abuse measures may have flagged your account for any of the following behaviors: Sending a large number of direct messages in a short span of time Participating in a server dedicated to spamming Discord Automating your user account or self-botting Taking other actions on Discord - for example, joining a ton of servers - faster than humanly possible Attempting potentially fraudulent activity Sincerely, Discord Trust & Safety ... & NO contact information... ... So that is me & Discord well & truly parting company...
@@ElTelBaby Sorry to hear that but this is definitely something you need to take up with Discord. You could register another account using a different email address.
@@LearnElectronicsRepair Twitter used to have similar systems that ran in the old days, lost count of the accounts they blocked thinking i was a robot. There are many ways to skin a cat and Discord is just one of them. Don't sweat it. They will ever make mistakes.
NOTES - PLEASE READ
03:36 - This looks like a transfomer winding with a centre tap, however I checked the resistance of the winding at one point (not in the video). It turns out that resistance across the whole winding is about 20 ohms and the resistance from the 'tap' to one end is 2 ohms. At first I wondered if it was faulty, then I figured it is a tapped primary but the tap point is not in the centre of the winding. This acts as an auto-transformer (like a normal step down transformer but with no mains isolation) so that the tap winding would have 10% of the voltage across it (based on the ratio 20 ohms to 2 ohms).
With a 240V AC mains supply the tap voltage would be 24V AC and this is what I think it is doing - either acting as a low voltage supply to part of the circuit or the 24V is being monitored by the microcontroller to calculate the output (240V) voltage
46:43 - This requires a little more explanation. Basically an OP-AMP, or Operation Amplifier can be considered to be an amplifier with infinite gain. This means that even the smallest difference in voltage between the + and - inputs causes the output voltage to swing between 0V and the Power Supply Voltage (in our case 12V) Used like this the op-amp acts like a switch. If we put a reference voltage on one of the inputs it acts like a voltage comparator.
However we can also set the gain of an op-amp using two resistors - one feedback resistor between the output and one of the inputs, and another resistor on the same or other input. The ratio between the two resistances sets the amplifier gain. When I spotted the feedback resistor I realised the op-amp in our circuit is being used to amplify the small voltage across the current sense resistor so that the microcontroller can measure it.
I will cover 'ALL YOU NEED TO KNOW ABOUT OP-AMPS TO FIX STUFF in a future video.
@03:36 If the UPS is a line-interactive one it may use the autotransformer to reduce o increase the ac output if the input is too high or low respectively.
Hi, At switch on May be it also test to see if the battery needs to be charged. I just joined your discord as Super-Grand-Ad.- Brill Video Chase to a duff battery.
The only answer I have is there is not another channel on TH-cam like yours. I was glued to my tv following along with theory. It was very enjoyable watching you go through the steps in a logical manor despite the outcome. Love your channel
The UPS's I work with on my job do this very thing - IF you install them and turn them on before you put the internal battery in, it will give an alarm and not start up. You have to turn it off, install the battery, then plug it in and turn it on. I don't understand all the internal workings of it, but even the older (15 year old UPS's) are like that. However, once you know that sequence, you tend to not make that mistake again. The UPS's I'm working with are 2kVA to 10kVA with internal and external battery packs. But from your video, even the single battery UPS's do this. I really enjoyed watching this because I have a lot of items with no schematics. I have several "doh!" moments as a result. Thanks for your channel. Really enjoying watching all your videos, and am learning a lot in the process.
Not sure but thought the original goal was to see if the board could be used/altered to become an inverter for a solar application. It seems we proved the UPS works, but did we lose track of the original goal? Love the vids! Happy when the bell goes off saying another one has been posted.
Your videos seem to be a bit long at first, but considering your knowledge and the way you explain things, these are excellent tutorial videos, i have learnt many things from your videos, and i thank you for that sir
Thank you for watching 🙂
I’m glad to see someone else have a moment like this. Now I know it’s not just me. I can’t tell you how many times I’ve spent hours chasing a theory only to find a simple solution.
Oh for sure it definitely isn't just you. I like to publish videos like this one just to show what it really is like even if you have a lot of experience. Best thing is you only get caught out once (usually) by each new situation, and learn something at the same time. I certainly did with this one
Your videos are brilliant, very informative and easy to follow. Thank you for all the time and effort you put in to making such great content.
Nice of the manufacturer to have such a descriptive silk screen on both the top and the bottom :-) . That makes it a lot easier to reverse-engineer.
Hi Rich, Good video.
The open loop gain of an OP-Amp is extremely high and we don't know if there is any loop gain control.
So you can't really measure the difference on the inputs accurately enough to know if one input is greater
than the other as it could be lower than the meters resolution can possibly read.
If you know how the gain is set then it could be worth trying to measure the difference.
Remember there are multiple ways to use OP-Amps, some examples, Inverting Amps, Non-Inverting Amps, Buffers and Voltage Followers.
You would need to reverse engineer the Op-Amp circuit to see how it is being implemented to really know whats happening there.
I have also been caught out trying to use a bench power supply with a UPS to find out it does not always work.
I think you will find that during the power up cycle it tests the installed battery to see it it charges, takes a load and if the AC is applied.
It seems they are not very efficient either.
The output voltage of those Gel Cells is around 11 - 13v but the charging voltage is quoted around the 14V mark.
Your last solution is definitely the way to go when testing these units.
9 out of ten times, when these units are discarded its because of faulty batteries, and the replacement batteries are almost as costly as the UPS, so they get dumped. Its quite easy to modify a UPS to use a car battery as long as you put the battery into a battery box that is in a well ventilated area.
Remember car batteries contain Acid and give off hydrogen gas when charging.
Have played with a few different manufacture's small backup ups's & found some of them need an ac input to start up. Fyi. Thankyou for your videos!
fantastic lesson about mosfet thanks for posting this is a really good educational video :)
my new favorite channel
I suspect that the difference between a battery and a bench PSU is that you can have current going both ways, charge and discharge, with a battery but not with a bench PSU.
My guess is that the microcontroller looks to see if there's battery voltage and then switches to charging, where it monitors the charge current going to the battery. Because you were using a bench PSU, the microcontroller wouldn't see the charge current, or at least an incorrect charge current and shuts down thinking that it's connected to a faulty battery.
mmmm interesting I didn't think that you could be right.
Yeah. I added a comment like this. Then deleted it. Cos this comment says it better
I'm sure it's already been picked up, but the 4.4V on pin 3 @ 28.09 was actually on pin 2. Easy to do in a confined area!
Yeah, I even spotted that myself on watching the video.
Very interesting, fixing a stuff without schematic.
Lots of love Richard 💕💕💕
Azhar from India 🇮🇳
UPSes are non supposed to run on battery for long time so could the heatsink not be sized enough? I suggest at least to drill holes and maybe add a slow fan.
Yes that may be a good idea.. A fan and/or larger heatsink would be easy to add, especially with the internal battery removed. I need to fit some terminal posts to the enclosure anyway (to connect the battery once it is reassembled) so I'll take your advice and do that. Thanks.
I have done this very thing and can say adding a fan is a must if you want it to last for years instead of months.
Great learning video bud 🤙🏼🇦🇺, keep up the great content
I think the reason why it didn't work was, as a battery goes flat the internal resistance goes up and I think the circuitry is measuring the resistance of the battery and shuts the inverter down due to a lack of current flow. I'm still learning so it's a calculated guess.
My understanding of a battery's internal resistance is that it affects the current drawn out of the battery and the current limited into the battery. You may measure 12 volts on the battery with no load, but applying a load, you will see the voltage drop drastically. I use the "BLUE box" capacitor checker for testing the ESR on car batteries and 3V coin batteries. A TH-cam video showed it was save to use the Blue Box on battries.
I agree. But I was using my bench PSU which could deliver up to 5A and if you notice when I try to start the inverter it only draws a small amount - less than 100mA then switches off. I also tried a whole load of different voltage settings from 12V - 14.6V and it still would not start
@@LearnElectronicsRepair I’m curious if you would be able to measure the ESR of your bench power supply to see what that reading would be and maybe it would be a clue?
When you switch on ups it needs high current momentary and pure D.C. You can put large capacitor at O/P of the bench power supply, it may solve your problem.
I have another UPS to repair/mod. I will try your suggestion, thanks
Hi Richard. The comments from Ser Olmy and Sham Vibhute on this thread may explain what you saw. The internal resistance of a lead-acid battery would be a few milliohms, which means that its voltage will not drop even briefly. But the bench power supply perhaps doesn't have a huge internal energy store, and may rely more on internal feedback action to regulate any voltage dips under load. So if there is a sudden high current draw when the inverter starts up, the voltage of the bench supply may drop for a few milliseconds before it recovers. Something in the UPS inverter may be seeing that dip and not liking it.
Did you check whether or not the 'current sense' input pin to the MOSFET controller chip stays below 1 volt when the lead acid battery is used?
Maybe it's possible to see any voltage dip by looking at the bench supply with a scope set to AC coupled, and compare the depth of dip when using the lead acid battery to when using the bench supply.
The idea from Ser and Sham of putting big capacitor across the DC supply could be the answer. Or perhaps find how the voltage is sensed on the control PCB, and somehow modify the dip sensor to slow it down and so fool the circuit into staying on.
But then perhaps the solar cell that your friend wants to use actually have quite a low resistance so may be more like the lead-acid battery and it may just work, who knows?.
I think putting a big capacitor across the PSU output is a very good suggestion. Actually the owner brought me a second UPS to fix/modify so let's try that out soon.
The 'current sense' pin on the PWM controller I think is a red herring. I didn't completely reverse engineer the UPS but I think is it pretty certain it is not being used to sense current, but is being used as an EN signal from the micro-controller to the inverter PWM
Do you have a linear or switching bench power supply? I think it does a quick power test on the battery to see if it can deliver enough power to be stable. But it does this so quickly that your bench power supply meters don't pick it up. If you had a linear power supply you would be able to hear the relays click a switching power supply doesn't do that. It is just a guess it might also do this by reading the resistance of the battery like other people commented.
Actually I have one of each - the one I was using is SMPS but I also have a linear one. The guy who owns this one brought me another UPS to repair/modify so I am going to play around with that one too. I could try my linear PSU or put a large electrolytic across the PSU output as some here have suggested.
If you don't mind, can you pls share brand and type of your probes? Thx
Heya, I have a MPP Solar HV 4850 hybrid inverter. have bean wondering how that would work now I have seen a simpler virsion of what I have ( much more comment's inside, of cores I opened it and uploaded it to my youtube channel) but now I have a more clear picture of the working inside lol it thanks.
I think u need to hold the button down for 3 secs to force it on in a test state, red light suggests no mains as battery in discharge mode
very interesting video, it was interesting to learn about current sensing and voltage sensing to enable the PWM chip. Don't worry about chasing the red herring, I think it's part of been an electronics engineer 🙂
if you're looking for content to create how about operational amplifiers as they are very common component.
Make a video about Op Amps? Oh yeah I mentioned that in the NOTES -PLEASE READ which I pinned in the topics. I must have ESP 😉
Richard, are you sure this device is not designed to run with 24V batteries? I know some UPS run 2x 12v in series.
Also, what is the ripple like on your bench PS?
Hi! In a previous job I had about 30 of that exactly UPS. They are crap, do no use them, I had to change many batteries every 2 years, maybe floating mode is inexistent?. Gooooood video by the way!
Every 14 days, my UPS will run a self-test. This turns
on the inverter and measures what current it can draw
and presumably indicate when the battery has reached
the end-of-life. I assume it does a similar test when
switched on. That is quite a reasonable assumption.
I found out this by googling since this alarm is not
documented in the manual.
My battery expired and I came up with the brilliant
idea of using my used car battery instead of buying a
new one. However the UPS did not see the expected
voltage drop and would turn on the alarm. The only way
to reset the alarm is to disconnect the battery and
mains, press the power on switch for a bit and then
reconnect the battery and mains in that order before
powering on again.
Every 14-days there is this hassle and I did not like
rebooting my desktop PC so I had another brilliant idea
to cut the wire to the alarm/buzzer. Peace at last
until one day it died completely during a lightning
storm. I felt the side of the car battery and it was
unexpectedly warm. I dared not use it again and
purchased a new unit. Can a UPS invert indefinitely if
a large enough battery bank is connected? I think maybe
not.
The only reason I buy such a UPS is to act as a
lightning arrestor/surge suppresor. Why not just buy a
surge suppressor? That is becasue each surge zaps the
suppressor and eventually it does not help at all AND
you don't know when that life is reached and you run
out of protection. It is cheaper to sacrifice a UPS.
I hope this helps explain why substituting a power
supply instead of a battery is foolishness.
Sorry, I did not learn anything from this video. You make too many assumptions.
Nice video
I think those 8pin UC chips are emf sensitive dealing with them via low quality probes or tweezers would lead to a disaster! I have blown one chip and some mosfets during inspection.
If it senses the internal battery resistance why it needs to do it , as in safety issiues or complaint issiues when the thing underdelivers the rated output ?
How does it sense the battery resistance?
@@LearnElectronicsRepair in the end of the video you mentioned that it works normally with a battery as in it might check for the internal resistance before enabling the output . And when you only used bench power supply with given volatege it refused to normally operare. I am a bit rusty on battery resistances alhough I am aware even AA batteries have it. Question is why would manufacturer design the conditions logic to work that way, if it is a cruical factor to be operated from a battery source and not otherwise.
Maybe the internal resistance of a lead acid battery is lower than that of a power supply ?
Possibly - but seeing as the power supply was the only thing powering the circuit I can't work out how it knows the internal resistance of it's own power supply
Sorry I got lost on how the unit was sensing difrence between power supply and batt but an interesting video all the same
I don't know how it was sensing the difference between Power Supply and battery either. At the end I ask you guys if anyone knows
@@LearnElectronicsRepair I had a similar issue trying to run a 24V UPS from a bench power supply. Turned out the short current spike caused by the UPS running an inverter self-test at power up was enough to trigger the current limiter of my 5A supply, which in turn triggered some battery sensing circuitry in the UPS.
In my case, a 10,000µF (or it might have been 15,000µF, I'm not quite sure) capacitor in parallel with the bench power supply was enough to deal with the current spike.
Thanks sir
I'm curious... Been workn on a project for over a year!... Can anyone find detailed wiring schmatics/pinouts for the two boards on this controller?... I can pay you in Ramen-Noodles...
Jungheinrich Steuerung MP 1510 C/6 Mat Nr 50313640 Interface 50053044
They always need a new battery.
Your likely not going to get a "current sense" trigger without a bahtree.
How does it sense a battery versus a power supply of the same voltage?
@@LearnElectronicsRepair It's a battery "MANAGEMENT" system.... Probably through an algorithm of sorts embedded within one of those chips... is there not an eprom on that board?
@@TH-camSupportServices Agreed - though there was no dedicated battery management chip. There is no discrete eprom but I am sure the micro controller contains firmware. While I agree with what everyone says about somehow detecting the battery resistance (I suggested so much in the video that is why I decided to try a good battery) I can't figure out why it would not work on my bench PSU - it only draws a small amount of power
@@LearnElectronicsRepair I have a couple boards laying around here someplace, ..I'll see If I have any of those chips.
@@LearnElectronicsRepair Found the boards..I'll look at them in the light tomorrow... If I find anything similar, ..maybe I'll just mail the parts to play with em....
make short video sir
What would you like to se a short video about?
@@LearnElectronicsRepair no sir I'm not well in English........ As you say explinarion Deeply it feels like learners some confusion..... So I request you teach slowly for learners.... Tq
I am a real dummy, but I do know that this type of circuit requires a full condition through the battery.,??.
5amp warning will go off if you have less than 17amps ish the invert low power warning will not power on and beep at you. The opto coupler switch on the high current side because the current is too high to use any relay. The best way to test this is with a fully charged battery or car battery. Worked with inverters for 10 years. Also you will never use this circuit with solar without some serious thinking and or bastardisation.
The guy who runs his house completely off solar actually uses his panels to charge an array of 12V batteries. I would expect this UPS would work as an inverter from the batteries but take on board what has been suggested by others here about fitting a larger heat sink / fan. As there is a lot of space where the original battery went that should not be a problem.
Other that that what other problems would you anticipate?
@@LearnElectronicsRepair Yep thanks for the reply just thing this ups is inverter is light duty and only designed to run for short periods. So yes it could be done but it's no man enough for long duty or heavy loads.
🤔🤔🤔🤔😂😂
Trying 2 sign in;... create an account with Discord;... which turned out 2 B RUBBISH...
Gave an email clicked all the DAM Right Images...
Got a verification email
Then it asked 4 a Phone number;... which sent me a code...
It then asked me to sign in;... which request me to go through all the above again
Then I received an email saying ACCOUNT Blocked as it has detected a BOT...
So STUFF Discord...
The link works for me - I just tried it. Give it another go
Learn Electronics Repair is now on Discord! Come and join the fun and let's fix stuff together, it's free and a nice place to be. discord.gg/vam6YC8vwU
@@LearnElectronicsRepair ...
This time it said Log Out at the bottom... But nothing seemed to work...
Log out;... then Logged back in...
Then it said Account Disabled...
Discord as also sent me a email stating...
...
Hello,
Discord is focused on maintaining a safe and secure environment for our community. We've found your account to be in violation of our Terms of Service or Community Guidelines. As a result, we've disabled your account for the following reason:
Discord has disabled your account for spam and/or platform abuse. Our anti-abuse measures may have flagged your account for any of the following behaviors:
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...
& NO contact information...
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So that is me & Discord well & truly parting company...
@@ElTelBaby Sorry to hear that but this is definitely something you need to take up with Discord. You could register another account using a different email address.
@@LearnElectronicsRepair Twitter used to have similar systems that ran in the old days, lost count of the accounts they blocked thinking i was a robot. There are many ways to skin a cat and Discord is just one of them. Don't sweat it. They will ever make mistakes.
Excelente video... Please you can bring your email... I need to ask something... Thanks